John Dobereiner proposed the idea of similarity in the properties of elements which can be placed together.
He proposed the idea of classification so that we can study the properties of a group of elements together
According to him, three elements can be grouped based on their similarities in properties. This group of three elements was termed as "Triads"
For example :
Li, Na, K
Now the significance of the triad was that the atomic weight of middle element is average of atomic weights of the side atoms
So atomic weight of Na = 23 is average of atomic weights of Lithium and Potassium
7 + 39/2 = 46/2= 23
The other triads were
Ca Sr Ba
Cl Br I
S Se Te
The minimum amount of energy that has to be added to start a reaction is the activation energy, which starts the reaction. It activates it.
Answer: I believe it’s the second one
(F)
Explanation:
We have that
- The Element with 49 protons is Indium
the isotope symbol in the one-line format
- We have that this is a cation
From the question we are told
An ionic isotope has 49 protons, 50 electrons, and 55 neutrons.
• What is the name of the element?
What is the isotope symbol in the one-line format (e.g., hydrogen-2)?
Is this a cation or is this an anion? Explain how you know.
Generally
Generally an isotope is an a variant form of a element bearing different number of Neutrons but same Proton
Therefore
For an isotope with 49 protons, 50 electrons, and 55 neutrons.
- The Element with 49 protons is Indium
the isotope symbol in the one-line format
- We have that this is a cation
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